Method of making separable fasteners



Jan. 18, 1938. e. SUNDBACK 2,106,129

METHOD OF MAKING SEPARABLE FASTENERS v Filed Feb. 4, 1955 2 Sheets-Sheetl Jan. 18, 1938. asuNDBAcK 2,106,129

METHOD OF MAKING SEPARABLE FASTENERS Filed Feb. 4, 1935 2 Sheets-SheetINVENTOR. Gideon Sundbac k srA'rEs METHQD F MAKINERSSEPABABLE FASTEN-Gideon Snndback, Meadville, Pa., assignor to Talon, Inc., Meadville,Pin, a corporation of Pennsylvania Application February 4, 1935, SerialNo. 4,794

12 Claims.

My invention relates to the art-of making fastener stringers,particularly for fasteners of the type'having multiple series of spacedelements attached along the corded edge of a flexible tape. A pair ofsuch fastener stringers are usually fitted with a slider for engagingand disengaging the fastener elements.

This application is a continuation in part of my copending application,Serial No. 414,156, filed December 14, 1929, now Patent No. 1,992,- 253,dated February 26, 1935,- in which there is disclosed a new and improvedform of wire fastener element, for the making of which my invention isespecially adapted. It is to be understood, however, that the methodinvention claimed in this application is not limited to any particularform of element since the interlocking construction as well as otherfeatures may be varied in many ways.

Slide fastener stringers have been manufactured by various methods inmost of which a fiat metal blank is cut out with spaced clamping jawsfor attaching the element to a stringer, and with a head at the otherend. After the blank is out it is usually placed in a suitable die andby operation of a reciprocating punch a projection and recess are formedon the head end.

An important object of this invention is to provide a slide fastenerwhose elements are smooth and free from so-called tool marks and otheruneven surfaces.

In the ordinary die forming of a blank which has been punched out ofsheet metal, during the operation in which the recess and projection aresimultaneously formed, the metal swells in all directions, causinguneven outer surfaces. This is particularly true after the die hasbecome somewhat worn.

Furthermore, the original surface of a blanked element or of one whichhas been severed from a formed wire may be uneven or, at least haveuneven and sharp corners. By using the original surfaces of a wire asthe finished external surfaces of the fastener elements-I am able tosecure a smoother fastener than has been known before.

In my improved method the projection and recess are formed in distinctand separate operations. One advantage of this is that the entirethickness of the metal is not placed under heavy forging pressure whichwould cause swelling and distortion of the outer surfaces of thefastener member.

Another object of theinvention is to provide a method of makingthe'recess and projection at the bend in a wire fastener element whetherthe wire be round or square, in such'a way that the placing of metalwill not materially weaken the fastener element at the bend. It will beunderstood that this might easily proveto be the weak point of thefastener since the clamping effect of the jaws depends on the strengthof the element at the bend. I

My invention also contemplates a new sequence of steps in makingfastener stringers. Instead of forming the elements with the desiredinterlocking projections and recesses before attaching them to the tape,the blanks are first secured firmly to the tape in properly spacedrelation, and then the interlocking projections or recesses, or both,areformed. In this way the problem of locating and holding the smallelements while being operated upon by punches and dies is simplified.

Various other objects and advantages of my invention will appear duringthe following specification and will be particularly pointed out in theclaims.

In the accompanying drawings, I have shown for purposes of illustration.two embodiments which my invention may assume in practice. In thesedrawings: 7

Figs. 1 and 2 are diiferent views .of a wire blank used in making afastener element from round wire;

Fig. 3 is a plan view of a small section of fastener stringer after thewire blanks are secured thereto andbefore the interlocking means areformed;

Fig. 4 is a transverse section through the stringer in Fig. 3; v

Fig. 5 is a perspective view showing diagrammatically the tools for,forming the interlocking recess; I

Fig. 6 is an elevation view showing diagrammatically the tools forforming the interlocking projection; r

Fig. 7 is a longitudinal section through a small portion of a fastenershowing the construction of a typical fastener element .formed fromround wire; 7 Y

Fig. 8 is a transverse section through the fastener showing theprojection side of the element; I

Fig. 9 is a front view of a fastener element;

Fig. 10 is a plan view of a completed fastener made in accordance withmy invention with the top portion of the slider removed to facilitateillustration;

Fig. 11 is a cross-section through the die with Figs. 13 and 14 arevarious steps in a modified method wherein a wire of squarecross-section is preformed and cut 011;

' the tape 2| with its attached U-shaped blanks Fig. 15 shows the wirein cross-sectio with the preforming tools diagrammatically illustrat-,ed;

Fig. 16 is a perspective view of the preformed wire element ready forbending;

Fig. 1'7 shows the next step of the method wherein the blank is bent toU-shape;

Fig. 18 shows the step of forming the recess and also the step offorming the projection;

Figs. 19 and 20 show the following step of forming the clamping jaws;

Fig. 21 shows the step of spreading the jaws and Fig. 22 shows the laststep of. closing the jaws on the beaded edge of a tape; and

Fig. 23 is a view of a slide fastener made ac-. cording to the secondembodiment of the invention. A

Referring to Figs. 1 and 2, a blank II is cut from a piece of round wireand formed with suitable means such as indentations l2 adjacent the endsof the blank to engage around the corded edge of the tape when themember is clamped to the stringer. In this form the wire blanks may betumbled to remove all burrs and hoppered by any suitable mechanism suchas described in my Patent No. 1,653,320. The indentations I! may, ifdesired, be formed at some latter stage of production such as describedin said patent.

In this embodiment of the invention the next step comprises bending thewire blank around. 'the corded edge 20 of a stringer 2| and thussecuring the blanks firmly to the stringer in the proper spaced relationfor the finishedfastener elements. The, member in this form comprisesU-shaped element with clamping sides or legs l3, l1 and a bend l5. It isnow necessary to form the interlocking projection and recess at the bendII. There stepsmay occur simultaneous or either may precede the other.

Fig. 5 illustrates the forming of the recess. During this operation itwill be understood that having a forming end 25 which moves into theblank at an acute angle between a pair of adjacent elements on thestringer. By reason of this kind of movement the material which isdisplaced. to form the recess It, moves inwardly toward the inside ofthe bend as seen in Fig. '7 whereby the resulting structure is notweakened.

The forming of the interlocking projection is 'shown in Fig. 6. The sideoperating tools 28 and and 26a enter: between the blanks along thestringer and support each of the elements in turn while the projectionis being formed. The tool for forming the projection is indicated by thenumeral 21 and is provided with a suitable forming edge which pushesdownwardly the material on the outer front surface of the blank ps0 asto form a projection l'l. 'Only a small amount of material need 'bemoved in this operation so that, the resulting member is not materiallyweakened. By forming the projection and recess in two separateoperations, the shape and size of the one is not controlled by theother.

This method results in a fastener as shown in Fig. 10, havinginterengaging recesses and projections l6 and i1 respectively, andsloping front end surfaces l8, which assist in guiding the members intoengagement with one another.

strength materially, is however, common to both methods.

In the second method I start with a wire 3| of square cross-section, itbeing understood that the corners will have a substantial radius inorder that they will be smooth to the touch.

. A section of this shape may readily be formed by extruding or bysimple rolling operations.

The first steps are the cutting of the wire into individual lengths andthe preforming ofthe wire to provide recesses '32 having anunsymmetrical shape, as illustrated. This preformlng mayibe done. beforecutting .of the blanks or afterwards, by suitable reciprocating tools,such as illustrated at .33 and 30 or by rotary die members. Theserecesses are formed so as to extend across one corner of the wiresection and the forming ofthese recesses leaves a portion .of metal 36in the middle which has been somewhat enlarged during the forming of therecesses. After bending of this preformed element into the'shape shownin Fig. 17, the portionof metal" is left at the bend and can be utilizedfor forming the projection. The forming of the projection and recess isindicated in Fig.18, and is'carried out by suitable forming tools 36,31, which act similarly to the forming tools 21. 24 respectively in thefirst method.

The next step as illustrated in Fig. 19, comprises punching outtherecesses 38, 39 leaving one leg ll of the bent member thicker thanthe' other leg I. The'punch and die which cut out the recesses 38, 39are, of course, slightly ofl center with respect to the fastenerelement. The punch and die are indicated at 2, 43. This punching outoperation leaves the surfaces on the inside of the legs 40 and ll veryrough with burred edges which tend to make the legs more securely gripthe corded edge-of the tape when clamped thereto, holding the fastenermembers in place, thus eliminating any danger of the members slippingout of place along the corded edge. It is now necessary to spread theselegs or at least one of them before placing the members on thecordededge of the tape. In the spreading operation, preferably only theleg 40 is bent as shown in Fig. 21. The final step comprises closing ofthis leg 43 around the corded edge of the tape 2| by any suitable tools,one of which is illustrated at M. It has .a somewhat differentappearance from the fastener of Fig. 10 inthat the sides will.

be fiat and smooth. All rough corners and-burrs.

however, can be removed by tumbling of the.

members either in the form shown in Fig. 16 or wire leaves side slopingsurfaces 43 which make the fastener more easily flexible without becomaFig. 17. In this fastener the preforming of the e ing a piece ofmaterial from original uniform.

ing disengaged. The slider for operating this fastener is indicated bythe numeral 46.

While I have specifically shown and described in this application twoembodiments which my invention may assume in practice, it will beunderstood that these embodiments are merely for the purposes ofillustration and descriptio isand that various other forms may bedevised within I the scope of my invention as defined in the followingclaims.

What I claim as my invention is:

l. The method of making fastener elements comprising forming attachingmeans on each fastener member for securing it to a tape, a portion ofthe member being adapted to project beyond the attaching means, punchingout a recess in one side of such projecting portion of said member, anddeforming material from an outer surface of said member to provide aprojection opposite said recess.

2. The method of making a fastener element comprising forming a clampingportion adjacent one end of the element, providing interlocking means atthe other end by steps including punching out a recess on one side ofsaid element with a punch moving at an acute angle to the plane of saidelement so as to deform the material from said recess in the plane ofsaid element in a direction toward the clamping portion? .1"

3. The method of making a fastener elemen comprising bending a piece ofwire to form clamping portions between the ends of the wire, deformingmaterial from adjacent the bend toward said clamping portions to form arecess, and forming an interlocking projection, on the bend of saidwire.

4. The method of'making a fastener element comprising bending a piece ofsubstantially round wire to form parallel side portions and a connectingportion at the bend, deforming material, wholly from the outer side ofsaid bend on then front of said element to form a' projection on oneside of said connecting-portion, and punching out a recess wholly in theother side of said connecting portion.

5. The. method of making a fastener stringer which comprises cutting aplurality of blanks, attaching them in spaced relation to the edge of apiece of material, and deforming the material of each of said blankswhile so attached to form interlocking projections and recesses.

16. The method of making fastener stringers for slide fasteners whichcomprises securing fastener member blanks to said stringers along theadjacent edges thereof, said blanks being of the approximate size andshape of the finished fastener element and having the same spacing asthe elements of a finished fastener, and then operat ing on theprojecting portions of each of said blanks to complete the formation ofinterlocking projections and recesses.

7. The method of making a fastener elementfor attachment to 'a flexiblestringer inthe manu 'facture of slide fasteners, which comprisesforgcross-section to concentrate material at the cen-' tral portion ofsaid piece of material, bending said piece of material to U-shape withsaid eoncentrated portion at the bend, the legs of said 5 U-shapedmember constituting means for em-.

bracing and'clamping the edge of a stringer, and

deforming material at said bend after the bend-' ing operation toprovide an interlocking projection and recess. a

8. The method of making a fastener element for attachment to a flexiblestringer in the manufacture of slide fasteners, which comprises forginga uniform piece of material from" uniform cross-section to concentratematerial at the cen- 15 tral portion thereof and to provide indentationson opposite sides of said enlarged portion, bending said piece ofmaterial to U-shape with said enlarged portion at the bend, the legs ofsaid U-shape member constituting means for embrac- 20 ing and clampingthe edge of a stringer, and deforming material at said bend after thebending operation to provide an interlocking projection on one side andan interlocking recess on the opposite side. 25

9. The method of making a fastener element for attachment to a flexiblestringer in the manufacture of slide fasteners, which comprises forginga uniform piece of material from uniform cross-section to concentratematerial at the central portion thereof and to provide indentations onopposite sides of said enlarged portion, bending said piece of materialto U-shape with said enlarged portion at the bend, forming recesses inthe opposed faces of the leg portions of said bent member to providemeans for engaging the beaded edge of a flexible stringer.

10. The combination defined in claim 10 with the further step ofspreading said legs apart to facilitate assembly with the beaded edge ofthe 40 flexible stringer.

'11. The combination defined in claim 10 wherein the recess in one ofsaid leg portions is deeper than the opposite recess to make one legweaker against bending stresses than the opposite leg.

12. The method of making fastener elements for attachment to a flexiblestringer in the manufacture of slide fasteners which comprises forging apiece of material of generally square cross-section to provide anenlarged portion at 50' the middle with material concentrated along onecorner of said piece of material, and to form indentations extendingacross the same corner, and the opposite sides of said enlarged portion,bending said piece of material to Usha'pe in sucha way that-the parallellegs of the bent member have flat faces opposite each other and withsaid enlarged portion at the bend, and then forging the material at saidenlarged portion to provide an interlocking projection on one side ofthe 50 member and forming an interlocking recess on the opposite side ofsaid member.

GIDEON SUNDBACK.

